The present invention pertains to a balancing personal vehicle having a support for a human subject, the support being pivotable in order to allow the subject to be supported at a desired angle with respect to ground contacting elements of the vehicle.
Personal vehicles may be self-propelled and user-guidable, and, further, may entail stabilization in one or both of the fore-aft or left-right planes, such as whey no more than two wheels are in ground contact at a time. Vehicles of this sort may be operated in a mode in which motion of the vehicle, including acceleration (both linear and turning), is controlled partially or entirely by leaning of the vehicle as caused by a subject riding the vehicle. Several such vehicles are described in U.S. Pat. No. 5,971,091, issued Oct. 26, 1999, which is incorporated herein by reference.
Such balancing vehicles may lack static stability. Referring, for example, to FIG. 1A, wherein a prior art personal transporter is shown and designated generally by numeral 18, a subject 10 stands on a support platform 12 and holds a grip 14 on a handle 16 attached to the platform 12, so that the vehicle 18 of this embodiment may be operated in a manner analogous to a scooter. A control loop may be provided so that leaning of the subject results in the application of torque to wheel 20 about axle 22 thereby causing an acceleration of the vehicle. Vehicle 18, however, is statically unstable, and, absent operation of the control loop to maintain dynamic stability, subject 10 will no longer be supported in a standing position and will fall from platform 12. Another prior art balancing vehicle is shown in FIG. 1B and designated generally by numeral 24. Personal vehicle 24 shares the characteristics of vehicle 12 of FIG. 1A, namely a support platform 12 for supporting subject 10 and grip 14 on handle 16 attached to platform 12, so that the vehicle 18 of this embodiment may also be operated in a manner analogous to a scooter. FIG. 2 shows that while vehicle 24 may have clusters 26 each having a plurality of wheels 28, vehicle 24 remains statically unstable and, absent operation of a control loop to maintain dynamic stability, subject 10 will no longer be supported in a standing position and may fall from platform 12.
In accordance with a preferred embodiment of the invention, there is provided a device for transporting a human subject over a surface. The device has a platform defining a fore-aft plane that supports a payload including the human subject. The device also has a ground-contacting module that includes a ground-contacting member movably coupled to the platform. The platform and the ground-contacting module are components of an assembly, and the position of the center of gravity of the assembly is defined with respect to the ground-contacting member. The device also has a support for supporting the subject, where the support is coupled to the platform in such as manner as to permit variation in the fore-aft plane of the position of the center of gravity. Furthermore, the device has a drive, coupled to the ground contacting module, for delivering power to the ground-contacting module in a manner responsive to the position of the center of gravity.
In accordance with alternate embodiments of the present invention, the support includes a seat. The support may be coupled to the platform at a pivot oriented to allow motion of the support about an axis substantially transverse to the fore-aft plane. The device may have a handle, affixed to the platform, having a grip at approximately waist height of the subject, so that the device may be operated in a manner analogous to a scooter. The ground-contacting module may be characterized by a region of contact with the ground and the support may have an articulated member, biased for supporting a portion of the weight of the subject, and the support may have a region of local stability substantially above the region of contact with the ground of the ground-contacting module.
In accordance with a further embodiment of the invention, there is provided a device for carrying a user, wherein the device has a platform and a user support having a position defined with respect to the platform and coupled to the platform in such a manner that the user may vary the position of the support with respect to the platform in the course of normal operation of the device. The device also has a motorized drive that propels the platform over an underlying surface through motion of at least one ground-contacting member and a controller, coupled to the motorized drive, for governing the operation of the motorized drive at least in response to the position of the user support.
In accordance with yet a further embodiment of the invention there is provided a device for conveying a seated user. The device has a platform for supporting a payload including the seated user, a ground-contacting module mounted to the platform that propels the platform with respect to an underlying surface, and a drive, coupled to the ground-contacting module, for delivering power to the ground-contacting module in a manner controlled solely by leaning of the user.